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Pongamia seedpods are recognized as a potential feedstock for sustainable aviation fuel production due to the relatively high oil content of the seeds. Pongamia pods are byproduct residues available after seed separation. Pods have high chlorine and potassium content that may be problematic in thermochemical energy conversion systems. Leaching experiments were performed to remove inorganic constituents of pods and thereby reduce the potential for fouling, slagging, and agglomeration. A 23 factorial design determined the impacts of process operating parameters (i.e. rinse water temperature (25 °C vs. 75 °C), rinse duration (10 min vs. 2 h), and particle size (

Surface characterization techniques (scanning electron microscopy and X-ray photoelectron spectroscopy) were used to examine toluene-insoluble solids from coprocessing of coal and heavy oil in order to evaluate their physical spearation potential. Washability studies, using float-sink tests, were also carried out to provide an empirical estimate of the ash separation attainable. On the basis of the results, agglomeration tests were performed in an attempt to optimize the beneficiation of the organic matter in the residue pitch. Ash rejection in these tests ranged from 30 to 40%. Analysis of the ash from the agglomerated and reject fractions suggested that most of the iron was retained in the agglomerates.

The beneficiation of fine coal using the oil agglomeration technique (spherical or liquid phase agglomeration) has been developed at the National Research Council of Canada over a number of years. In this present study the separation of pyrite and other non-carbonaceous materials from the coal particles by selective agglomeration with fuel oil and/or bitumen has been investigated. The oil agglomeration characteristics of freshly mined and agglomerated aged coals were also compared and found to depend on their relative hydrophobicity. An improved response for weakly hydrophobic coals was achieved by treatment with conditioning agents such as sodium oleate. Even after beneficiation, the Nova Scotia coal studied still contained up to 3 wt% of sulphur, and therefore sulphur emission control on combustion is likely to be necessary. It has been demonstrated that SO 2 adsorbents can be incorporated directly into coal or coke agglomerates during liquid phase agglomeration, using bitumen or heavy oil as the binder. Static combustion tests at 850 °C were carried out in a muffle furnace and compared with results found for a bench scale fluidized bed unit at the same temperature. In both cases, sulphur capture of over 60% was obtained at a calcium to sulphur molar ratio of 1:1.

The unique fuel flexibility of fluidised bed system facilitates the combustion of low quality solid fuels such as agricultural residues, but may suffer from serious bed agglomeration problems especially when operating at the high end of the typical fluidised bed combustion temperature range (800–900 °C). In this study, a 1.5 wt% lime addition to biomass fuels was investigated as a countermeasure to agglomeration for the combustion of pelletised wheat straw and miscanthus in a 20 kW bubbling fluidised bed (BFB) combustor using quartz sand as the bed material. Comparing to the widely studied agglomeration countermeasures such as bed additives and alternatives, the lime addition to fuel can provide a continuous on-site agglomeration counter action. Without lime addition, defluidisation as a result of bed agglomeration occurred once the bed temperature reached 860 °C and 877 °C for miscanthus and wheat straw respectively. However, with the lime addition, stable combustion could be achieved at 900 °C for both fuels with a substantially prolonged operation time. The obtained agglomerates were characterised using CAMSIZER, XRD and SEM/EDX and the results showed that the presence of lime in the fuel could significantly reduce the agglomerates size by forming high melting point calcium silicates/phosphates which hinder the K-rich molten substance attachment and result in heterogeneous coating layers in the agglomerates. The results of this study clearly indicate that using lime as fuel additive can realise the combustion of the problematic non-woody biomass fuels by considerably reducing the bed agglomeration propensity in practical fluidised bed combustion plants.